Miyazato will seek her 10th career LPGA title after ending the day at 19-under-par 197.
Making a move Saturday was Stacy Lewis, who is seeking the world No. 1 ranking with a victory. She fired a 6-under 66 to grab sole possession of second place at minus-17.
Jee Young Lee, meanwhile, fell off the pace after holding the second-round lead at JW Marriott Phoenix Desert Ridge Resort & Spa. She turned in an even-par round of 72 to end four shots back at minus-15.
Notable deaths of 2014 [PHOTOS]